In most PV systems, the voltage at which the power is generated by the PV modules differs from the operational voltage of the loads. Furthermore, if the PV system contains MPPT logic, the maximum power point voltage might vary throughout the day. Therefore a component is required in the PV system to convert the output voltage (and current) of the PV modules. Additionally, if the PV system is grid-connected, or if certain types of loads are connected, the power has to be converted from direct current (DC) to alternating current (AC). In this section we will discuss the DC-DC converters, the DC-AC inverters will be discussed in the next section. This video serves as an introduction to the DC-DC converter.